Buggy code:
public Object createDataType ( String typeName ) throws BuildException { } public String getElementName ( Object element ) { } public String getElementName ( Object element , boolean brief ) { } private boolean validDefinition ( AntTypeDefinition def ) { } private boolean sameDefinition ( AntTypeDefinition def , AntTypeDefinition old ) { } private void updateDataTypeDefinition ( AntTypeDefinition def ) { } public void enterAntLib ( String uri ) { } public String getCurrentAntlibUri ( ) { } public void exitAntLib ( ) { } private void initTasks ( ) { } private ClassLoader getClassLoader ( ClassLoader classLoader ) { } private void initTypes ( ) { } private synchronized void checkNamespace ( String componentName ) { } public String diagnoseCreationFailure ( String componentName , String type ) { StringWriter errorText = new StringWriter ( ) ; PrintWriter out = new PrintWriter ( errorText ) ; out . println ( ( ( ( "Problem:<seq2seq4repair_space>failed<seq2seq4repair_space>to<seq2seq4repair_space>create<seq2seq4repair_space>" + type ) + "<seq2seq4repair_space>" ) + componentName ) ) ; boolean lowlevel = false ; boolean jars = false ; boolean definitions = false ; boolean antTask ; String home = System . getProperty ( USER_HOMEDIR ) ; File libDir = new File ( home , Launcher . USER_LIBDIR ) ; AntTypeDefinition def = getDefinition ( componentName ) ; if ( def == null ) { boolean isAntlib = ( componentName . indexOf ( ANTLIB_PREFIX ) ) == 0 ; out . println ( "Cause:<seq2seq4repair_space>The<seq2seq4repair_space>name<seq2seq4repair_space>is<seq2seq4repair_space>undefined." ) ; out . println ( "Action:<seq2seq4repair_space>Check<seq2seq4repair_space>the<seq2seq4repair_space>spelling." ) ; out . println ( "Action:<seq2seq4repair_space>Check<seq2seq4repair_space>that<seq2seq4repair_space>any<seq2seq4repair_space>custom<seq2seq4repair_space>tasks//types<seq2seq4repair_space>have<seq2seq4repair_space>been<seq2seq4repair_space>declared." ) ; out . println ( "Action:<seq2seq4repair_space>Check<seq2seq4repair_space>that<seq2seq4repair_space>any<seq2seq4repair_space><presetdef>//<macrodef><seq2seq4repair_space>declarations<seq2seq4repair_space>have<seq2seq4repair_space>taken<seq2seq4repair_space>place." ) ; if ( isAntlib ) { out . println ( ) ; out . println ( "This<seq2seq4repair_space>appears<seq2seq4repair_space>to<seq2seq4repair_space>be<seq2seq4repair_space>an<seq2seq4repair_space>antlib<seq2seq4repair_space>declaration.<seq2seq4repair_space>" ) ; out . println ( ( "Action:<seq2seq4repair_space>Check<seq2seq4repair_space>that<seq2seq4repair_space>the<seq2seq4repair_space>implementing<seq2seq4repair_space>library<seq2seq4repair_space>exists<seq2seq4repair_space>" + "in<seq2seq4repair_space>ANT_HOME//lib<seq2seq4repair_space>or<seq2seq4repair_space>in<seq2seq4repair_space>" ) ) ; out . println ( ( "<seq2seq4repair_space>" + libDir ) ) ; } definitions = true ; } else { final String classname = def . getClassName ( ) ; antTask = classname . startsWith ( "org.apache.tools.ant." ) ; boolean optional = classname . startsWith ( "org.apache.tools.ant.taskdefs.optional" ) ; optional |= classname . startsWith ( "org.apache.tools.ant.types.optional" ) ; Class clazz = null ; try { clazz = def . innerGetTypeClass ( ) ; } catch ( ClassNotFoundException e ) { out . println ( ( ( "Cause:<seq2seq4repair_space>the<seq2seq4repair_space>class<seq2seq4repair_space>" + classname ) + "<seq2seq4repair_space>was<seq2seq4repair_space>not<seq2seq4repair_space>found." ) ) ; jars = true ; if ( optional ) { out . println ( "<seq2seq4repair_space>This<seq2seq4repair_space>looks<seq2seq4repair_space>like<seq2seq4repair_space>one<seq2seq4repair_space>of<seq2seq4repair_space>Ant's<seq2seq4repair_space>optional<seq2seq4repair_space>components." ) ; out . println ( ( "Action:<seq2seq4repair_space>Check<seq2seq4repair_space>that<seq2seq4repair_space>the<seq2seq4repair_space>appropriate<seq2seq4repair_space>optional<seq2seq4repair_space>JAR<seq2seq4repair_space>exists<seq2seq4repair_space>" + "in<seq2seq4repair_space>ANT_HOME//lib<seq2seq4repair_space>or<seq2seq4repair_space>in<seq2seq4repair_space>" ) ) ; out . println ( ( "<seq2seq4repair_space>" + libDir ) ) ; } else { out . println ( "Action:<seq2seq4repair_space>Check<seq2seq4repair_space>that<seq2seq4repair_space>the<seq2seq4repair_space>component<seq2seq4repair_space>has<seq2seq4repair_space>been<seq2seq4repair_space>correctly<seq2seq4repair_space>declared" ) ; out . println ( "<seq2seq4repair_space>and<seq2seq4repair_space>that<seq2seq4repair_space>the<seq2seq4repair_space>implementing<seq2seq4repair_space>JAR<seq2seq4repair_space>is<seq2seq4repair_space>in<seq2seq4repair_space>ANT_HOME//lib<seq2seq4repair_space>or<seq2seq4repair_space>in" ) ; out . println ( ( "<seq2seq4repair_space>" + libDir ) ) ; definitions = true ; } } catch ( NoClassDefFoundError ncdfe ) { jars = true ; out . println ( ( "Cause:<seq2seq4repair_space>Could<seq2seq4repair_space>not<seq2seq4repair_space>load<seq2seq4repair_space>a<seq2seq4repair_space>dependent<seq2seq4repair_space>class<seq2seq4repair_space>" + ( ncdfe . getMessage ( ) ) ) ) ; if ( optional ) { out . println ( "<seq2seq4repair_space>It<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>enough<seq2seq4repair_space>to<seq2seq4repair_space>have<seq2seq4repair_space>Ant's<seq2seq4repair_space>optional<seq2seq4repair_space>JAR,<seq2seq4repair_space>you<seq2seq4repair_space>need<seq2seq4repair_space>the<seq2seq4repair_space>JAR" ) ; out . println ( "<seq2seq4repair_space>files<seq2seq4repair_space>that<seq2seq4repair_space>it<seq2seq4repair_space>depends<seq2seq4repair_space>upon." ) ; out . println ( "Ant's<seq2seq4repair_space>optional<seq2seq4repair_space>task<seq2seq4repair_space>dependencies<seq2seq4repair_space>are<seq2seq4repair_space>listed<seq2seq4repair_space>in<seq2seq4repair_space>the<seq2seq4repair_space>manual." ) ; } else { out . println ( "<seq2seq4repair_space>This<seq2seq4repair_space>class<seq2seq4repair_space>may<seq2seq4repair_space>be<seq2seq4repair_space>in<seq2seq4repair_space>a<seq2seq4repair_space>separate<seq2seq4repair_space>JAR<seq2seq4repair_space>that<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>installed." ) ; } out . println ( "Action:<seq2seq4repair_space>Determine<seq2seq4repair_space>what<seq2seq4repair_space>extra<seq2seq4repair_space>JAR<seq2seq4repair_space>files<seq2seq4repair_space>are<seq2seq4repair_space>needed,<seq2seq4repair_space>and<seq2seq4repair_space>place<seq2seq4repair_space>them" ) ; out . println ( "<seq2seq4repair_space>in<seq2seq4repair_space>ANT_HOME//lib<seq2seq4repair_space>or" ) ; out . println ( ( "<seq2seq4repair_space>in<seq2seq4repair_space>" + libDir ) ) ; } if ( clazz != null ) { try { def . innerCreateAndSet ( clazz , project ) ; out . println ( "The<seq2seq4repair_space>component<seq2seq4repair_space>could<seq2seq4repair_space>be<seq2seq4repair_space>instantiated." ) ; } catch ( NoSuchMethodException e ) { lowlevel = true ; out . println ( ( ( "Cause:<seq2seq4repair_space>The<seq2seq4repair_space>class<seq2seq4repair_space>" + classname ) + "<seq2seq4repair_space>has<seq2seq4repair_space>no<seq2seq4repair_space>compatible<seq2seq4repair_space>constructor." ) ) ; } catch ( InstantiationException e ) { lowlevel = true ; out . println ( ( ( "Cause:<seq2seq4repair_space>The<seq2seq4repair_space>class<seq2seq4repair_space>" + classname ) + "<seq2seq4repair_space>is<seq2seq4repair_space>abstract<seq2seq4repair_space>and<seq2seq4repair_space>cannot<seq2seq4repair_space>be<seq2seq4repair_space>instantiated." ) ) ; } catch ( IllegalAccessException e ) { lowlevel = true ; out . println ( ( ( "Cause:<seq2seq4repair_space>The<seq2seq4repair_space>constructor<seq2seq4repair_space>for<seq2seq4repair_space>" + classname ) + "<seq2seq4repair_space>is<seq2seq4repair_space>private<seq2seq4repair_space>and<seq2seq4repair_space>cannot<seq2seq4repair_space>be<seq2seq4repair_space>invoked." ) ) ; } catch ( InvocationTargetException ex ) { lowlevel = true ; Throwable t = ex . getTargetException ( ) ; out . println ( "Cause:<seq2seq4repair_space>The<seq2seq4repair_space>constructor<seq2seq4repair_space>threw<seq2seq4repair_space>the<seq2seq4repair_space>exception" ) ; out . println ( t . toString ( ) ) ; t . printStackTrace ( out ) ; } catch ( NoClassDefFoundError ncdfe ) { jars = true ; out . println ( ( ( "Cause:<seq2seq4repair_space>A<seq2seq4repair_space>class<seq2seq4repair_space>needed<seq2seq4repair_space>by<seq2seq4repair_space>class<seq2seq4repair_space>" + classname ) + "<seq2seq4repair_space>cannot<seq2seq4repair_space>be<seq2seq4repair_space>found:<seq2seq4repair_space>" ) ) ; out . println ( ( "<seq2seq4repair_space>" + ( ncdfe . getMessage ( ) ) ) ) ; out . println ( "Action:<seq2seq4repair_space>Determine<seq2seq4repair_space>what<seq2seq4repair_space>extra<seq2seq4repair_space>JAR<seq2seq4repair_space>files<seq2seq4repair_space>are<seq2seq4repair_space>needed,<seq2seq4repair_space>and<seq2seq4repair_space>place<seq2seq4repair_space>them" ) ; out . println ( "<seq2seq4repair_space>in<seq2seq4repair_space>ANT_HOME//lib<seq2seq4repair_space>or" ) ; out . println ( ( "<seq2seq4repair_space>in<seq2seq4repair_space>" + libDir ) ) ; } } out . println ( ) ; out . println ( "Do<seq2seq4repair_space>not<seq2seq4repair_space>panic,<seq2seq4repair_space>this<seq2seq4repair_space>is<seq2seq4repair_space>a<seq2seq4repair_space>common<seq2seq4repair_space>problem." ) ; if ( definitions ) { out . println ( ( "It<seq2seq4repair_space>may<seq2seq4repair_space>just<seq2seq4repair_space>be<seq2seq4repair_space>a<seq2seq4repair_space>typographical<seq2seq4repair_space>error<seq2seq4repair_space>in<seq2seq4repair_space>the<seq2seq4repair_space>build<seq2seq4repair_space>file<seq2seq4repair_space>" + "or<seq2seq4repair_space>the<seq2seq4repair_space>task//type<seq2seq4repair_space>declaration." ) ) ; } if ( jars ) { out . println ( "The<seq2seq4repair_space>commonest<seq2seq4repair_space>cause<seq2seq4repair_space>is<seq2seq4repair_space>a<seq2seq4repair_space>missing<seq2seq4repair_space>JAR." ) ; } if ( lowlevel ) { out . println ( ( "This<seq2seq4repair_space>is<seq2seq4repair_space>quite<seq2seq4repair_space>a<seq2seq4repair_space>low<seq2seq4repair_space>level<seq2seq4repair_space>problem,<seq2seq4repair_space>which<seq2seq4repair_space>may<seq2seq4repair_space>need<seq2seq4repair_space>" + "consultation<seq2seq4repair_space>with<seq2seq4repair_space>the<seq2seq4repair_space>author<seq2seq4repair_space>of<seq2seq4repair_space>the<seq2seq4repair_space>task." ) ) ; if ( antTask ) { out . println ( ( "This<seq2seq4repair_space>may<seq2seq4repair_space>be<seq2seq4repair_space>the<seq2seq4repair_space>Ant<seq2seq4repair_space>team.<seq2seq4repair_space>Please<seq2seq4repair_space>file<seq2seq4repair_space>a<seq2seq4repair_space>" + "defect<seq2seq4repair_space>or<seq2seq4repair_space>contact<seq2seq4repair_space>the<seq2seq4repair_space>developer<seq2seq4repair_space>team." ) ) ; } else { out . println ( "This<seq2seq4repair_space>does<seq2seq4repair_space>not<seq2seq4repair_space>appear<seq2seq4repair_space>to<seq2seq4repair_space>be<seq2seq4repair_space>a<seq2seq4repair_space>task<seq2seq4repair_space>bundled<seq2seq4repair_space>with<seq2seq4repair_space>Ant." ) ; out . println ( ( ( "Please<seq2seq4repair_space>take<seq2seq4repair_space>it<seq2seq4repair_space>up<seq2seq4repair_space>with<seq2seq4repair_space>the<seq2seq4repair_space>supplier<seq2seq4repair_space>of<seq2seq4repair_space>the<seq2seq4repair_space>third-party<seq2seq4repair_space>" + type ) + "." ) ) ; out . println ( "If<seq2seq4repair_space>you<seq2seq4repair_space>have<seq2seq4repair_space>written<seq2seq4repair_space>it<seq2seq4repair_space>yourself,<seq2seq4repair_space>you<seq2seq4repair_space>probably<seq2seq4repair_space>have<seq2seq4repair_space>a<seq2seq4repair_space>bug<seq2seq4repair_space>to<seq2seq4repair_space>fix." ) ; } } else { out . println ( ) ; <START_BUG> out . println ( "This<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>an<seq2seq4repair_space>bug;<seq2seq4repair_space>it<seq2seq4repair_space>is<seq2seq4repair_space>a<seq2seq4repair_space>configuration<seq2seq4repair_space>problem" ) ; <END_BUG> } } out . flush ( ) ; out . close ( ) ; return errorText . toString ( ) ; } private static class AntTypeTable extends Hashtable { private Project project ; AntTypeTable ( Project project ) { } AntTypeDefinition getDefinition ( String key ) { } public Object get ( Object key ) { } Object create ( String name ) { } Class getTypeClass ( String name ) { } Class getExposedClass ( String name ) { } public boolean contains ( Object clazz ) { } public boolean containsValue ( Object value ) { } } }

Fix:
out . println ( "This<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>a<seq2seq4repair_space>bug;<seq2seq4repair_space>it<seq2seq4repair_space>is<seq2seq4repair_space>a<seq2seq4repair_space>configuration<seq2seq4repair_space>problem" ) ;